ORD is DOA for the record... Might not even exceed the low from last night (-23) at this rate.
As for further west, there has been a real struggle to keep winds calm. Sites such as SQI/RPJ/ARR go calm and temps drop, then winds pick back up and the temp rises. The issue will likely continue for a while longer, before the ridge pushes in more towards morning. It's pretty clear that will be too late now though, so the state record is safe and it might be hard to find many sites that get below -30.